I hope you won’t think less of me if I confess something to you. Both of my intensely beloved, very much wanted and cherished children began life as contraceptive slip-ups. I’ll spare you the gory details (“Oh thank god!” I hear you sigh), but in both cases, a calculated gamble was taken in the heat of a particular moment and in both cases, the ball fell, or the cherries all lined up, or some other gambling-related double entendre occurred. In short, I got knocked up by mistake. Twice.

I am not alone in this. A (completely unscientific) poll among people I know suggests that up to half of the children in our social circle may not be the result of rigorous family planning and forward thinking but are instead the result of a missed pill/ bout of tummy flu so the pill failed, or a condom that split/came off/ never quite got put on in the first place. Indeed, as we’ve recently hit the seven-billion-people-on-the-planet mark, it should come as no big surprise that it can be really, really easy to make a baby by mistake.

What’s equally clear, as ten minutes of Jeremy Kyle, or indeed a trip to our local soft-play centre on a rainy day will show you, is that many, many people really should have put that condom firmly on, and shouldn’t have procreated at all. We’ve all seen children whose lives may well be ruined by their family circumstances. These children are born into homes where at best ignorance and apathy and at worst abuse and cruelty, can close doors for them and blight their hopes and dreams before they’ve had time to have any. It’s easy to make a baby. It’s a whole other ball game to raise a child. We all know a pet is for life, not just for Christmas, but kids stick around for a whole lot longer and need a lot more house training.

But what if a family hasn’t made a baby in the traditional mummy-loves-daddy-and-they-get-married-and-have-a-special-cuddle kind of way? What if the family has fostered, or adopted, or undergone medical treatment to create the baby? What if they have invested enormous time, effort and money to get the baby they have? What if they really, really are parents on purpose?

Let me tell you about three friends of mine. Wendy* is a foster mum. Her own children are grown up, and now she takes in children, often tiny babies, and cares for them until the courts decide if they can return to their biological parents, or they can be adopted. She raised one little boy from birth until he was nearly two before he went to his “forever” family. Do you have a two-year-old, or a child that was once two? Imagine giving away your child at two. Would it tear out your heart? Of course it would. She always knew she would have to give him away, but she still raised him with all the love, attention and cuddles you or I would give our own child. She didn’t skimp on the love at all, even though she knew loss was part of the equation.

Alan* read that babies in orphanages often don’t thrive because even though they’re fed and cared for, they don’t get held and cuddled, and babies need physical contact to survive. He volunteered at his local orphanage to hold and play with the babies. Very soon after he started, he lost his heart to a tiny baby girl, and got permission to bring her home for weekends. I first saw her when she was three weeks old, a grey, unresponsive baby who lay in her pram without moving. She didn’t cry – why bother? In the orphanage, the carers would always be too busy to respond. Alan got permission to foster the baby, and ultimately, to adopt her with his partner. By the time she was a year old, she was a chubby, boisterous and adorable toddler, full of giggles and first words. She is now nearly thirteen, a breathtaking beauty, a fine athlete and a good scholar. She has a younger brother, also adopted, and they have exceedingly bright futures.

Mary* and her partner desperately wanted children, but it wasn’t going to happen the conventional way so they saved all their money to undergo IVF. The first round failed. Sadly there isn’t a money-back guarantee. They aren’t rich people, so they had to save up again, and have another go. they are now parents to a beautiful baby boy. He may only be genetically related to one of them, but there isn’t a shadow of a doubt that they’re both his parents.

These are not the only people I know who have taken the parenthood-on-purpose route: there’s the couple in South Africa running a refuge for abandoned babies of HIV-positive parents. There’s a couple who chose to adopt a child whose birth circumstances meant he was certain to have developmental delays and problems, because they believed they had the love and resources to help such a child.

Now I’m not saying that these people are paragons of virtue, or perfect, or better than more conventional parents. But it does stand to reason that someone who has put that much effort into becoming a parent will take on the role with seriousness. They will probably have a degree of preparedness, financial planning and forward thinking that is at least equal to, if not superior to those of us who –accidentally or deliberately – made a baby the usual way.

Does it surprise you that of the families I mention above, more than half are gay or lesbian couples?

There’s a growing body of research (You can see some articles here, here and here) to suggest that gay and lesbian parents are just as good as heterosexual parents. Just as good, but not necessarily the same. They are different in that they tend to raise children who have more diverse groups of friends. Children of gay parents are often less restricted by conventional gender stereotypes in their career choices. But, incidentally, while they tend to raise more tolerant children, gay parents do not have any more gay children than straight parents do.

The American right, the Catholic Church and various other groups argue that the only correct way to raise children is in a nuclear family unit with a heterosexual man and woman who are married to one another. I think that’s not only a myth, but a dangerous one. The nuclear family is a very recent social construct. For centuries, children have been raised by extended families, by relatives, foster families, by communities and tribes. Maternal mortality, war, social change… all of these factors mean that “family” means very different things to different people. We think we know what ‘normal’ is, but is ‘normal’ really normal? And is it the only way that is right?

Maybe I’m a bit sensitive about strict definitions of family. I was a single mother for around ten years. I even claimed Jobseekers Allowance for six weeks in 2002, which (briefly) made me one of those benefit-scrounging layabout single mothers the right-wing press loves to hate. According to many people, I should have raised one of those NEET/ ASBO/ acronym kids, but instead, I raised a fine young man who does well academically, holds down a job and is a capable, contributing member of society. Whether the child is yours by blood, whether there’s a mum and dad, just a mum, a mum and a mum, a dad and a dad, a loving grandma, foster parent or sibling, what makes successful children is love, care and purpose.